And yet many in capitalist society lived and still live in abject poverty, despite the fact that there are enough resources so that no one should be left wanting. Nevertheless, you've somehow convinced yourself that those people either (a) don't matter, (b) deserve it, or (c) can't be helped.
If the goal is to reduce poverty, I fail to see how the existence of billionaires is a positive outcome, either now, in the form of Musk and his ilk; in the form of the robber barons of the late 18th century; or in the form of the noble lords of the feudal period to owned a lot but contributed nothing.
But not all "capitalist" societies have the same percentage in "abject poverty". So that makes me think that capitalism by itself is not the only major determinant of some of the bad things that we see, but rather the lack of interest and of focus to fix actual issues. Many societies can learn from others and improve their situation. Note: and many, if not most actually do, check : https://ourworldindata.org/grapher/the-share-and-number-of-p...
If the goal is to reduce poverty, the number of billionaire is actually irelevant. How you fund reducing poverty might influence the number of billionaires, but, for me it is more important what each society does for the poor, rather than counting how many are billionaires today.
It's not, but if the existence of billionaires correlates strongly with an increase in the median standard of living, I'm all for it. My politics are not driven by envy -- only what consistently produces the best outcome for the most.
Regarding the idea that we can design a system where "no one should be left wanting," that sounds nice. So does big rock candy mountain. There is no such system.